Field of the Invention
The present invention relates to a fuel pump module for a vehicle. More particularly, the present invention relates to a controller integrated fuel pump module by which deformation of a receiving part and a flange can be minimized and introduction of moisture between the receiving part and a molding part can be restrained.
Description of Related Art
As generally known in the art, a fuel pump module for feeding a fuel stored in a fuel tank to an injector of an engine is installed in the fuel tank of a vehicle.
A known fuel pump module includes a fuel pump, a filter for filtering a fuel pumped by the fuel pump to remove foreign substances, a reservoir cup in which the fuel pump and the filter are installed and fixed to a fuel tank, a bracket for fixing the fuel pump to the reservoir cup, and a flange (or holder cup) for fixing the fuel pump and the reservoir cup to the fuel tank.
Then, the fuel pump module is configured by bringing the fuel pump, the reservoir cup, and the filter into a module,
Recently, a variable pressure control fuel pump system has been developed and applied for the purpose of improving a fuel ratio of a vehicle, which system is a system for variably controlling a supply pressure of a fuel in real time in conjunction with an operation state of an engine.
A pressure sensor for detecting a supply pressure of a fuel fed by a fuel pump is installed in the variable pressure control fuel pump system, and a current pressure detected by the pressure sensor and a target pressure determined according to an operation state of the engine are compared and a supply pressure of the fuel is fed back in real time.
FIG. 1 is a diagram schematically showing a main configuration of a variable pressure control fuel pump system, which includes a battery 1 for supplying driving power, a fuel pump module 2 fixedly installed within a fuel tank (not shown), a pressure sensor 3 for detecting a supply pressure of a fuel supplied into an engine, a controller 4 for feedback controlling driving of a fuel pump (pump motor), and an ECU 5 for determining a target pressure according to an operation state of the engine while receiving breakdown diagnosis information from the controller 4 and transmitting the determined target pressure to the controller 4.
The pressure sensor 3 is installed in a fuel supply pipe connected from the fuel pump module 2 to the engine.
Meanwhile, in the conventional variable pressure control fuel pump system, the controller 4 is manufactured as a separate component in which a printed circuit board (PCB) to which various elements are mounted is embedded in a housing and is mounted to the fuel tank, in which case a controller mounting bracket for fixing the controller to the fuel tank is necessary.
In addition, complex electrical wirings and connectors for electrically connecting the controller and the pump motor are necessary, and components such as a clamp for fixing the electrical wirings to a periphery of the fuel tank is necessary.
As the configuration of the variable pressure control fuel becomes complex and the number of components such as an electrical wiring and a connector assembly, a controller housing, and a mounting bracket increases, the manufacturing costs of the system increase, and accordingly, it is difficult to apply the system to a large-sized luxury vehicle, a middle-sized vehicle, and a small-sized vehicle.
Switching noise of a switching element in the controller is radiated through an electrical wiring, and thus electrical noise becomes severe as an electrical wiring between the controller and the pump motor becomes longer.
Further, a performance of the pump motor (DC motor) is proportional to an applied voltage, in which case a voltage drop (0.1 V to 0.2 V) is generated as an electrical wiring between the controller and the pump motor becomes longer, and accordingly, a performance of the motor lowers.
In order to solve the above problems, as shown in FIG. 2, a controller integrated fuel pump module 10 obtained by receiving a PCB assembly 14 including a printed circuit board (PCB) 15 and various elements 122 in an interior space of a receiving part 12 provided in a flange 11, and molding and fixing the PCB assembly 14 with a molding material has been suggested.
In the controller integrated fuel pump module 10, a terminal (not shown) in which a molding part 130 and a flange 11 are integrally buried serves as an electrical wiring of a conventional controller while the molding part 130 enclosing the PCB assembly 14 serves as a housing of the conventional controller.
Thus, as compared with a conventional technology of providing a controller as a separate component and mounting the controller to a fuel tank, complex and long electrical wirings and connectors of the electrical wirings can be removed and a controller housing, a mounting bracket, and electrical wiring fixing components such as a clamp can be removed, whereby the number of components can be reduced and manufacturing costs can be reduced.
Further, excessive electrical noise and drop of a voltage applied to a motor that occur due to complex and long electrical wirings can be improved.
However, in the controller integrated fuel pump module 10, heat of the switching element (FET) mounted to the circuit board 15 is transferred through a heat dissipating member 125 and a terminal such that a size of the flange 11 (molded resin material) may be deformed and thus a sealed part of the tank may be deformed.
Further, since the flange 11 with which the receiving part 12 is integrally formed has an excellent surface roughness, bonding performance of the receiving part 12 and the molding part 130 is not good, whereby when bonding surfaces of the receiving part and the molding part are separated from each other, a short circuit may occur due to introduction of moisture.
Furthermore, due to expansion and contraction of the molding part, the flange may be deformed, and elements may be deformed and damaged, so that pores may be generated in the interior of the molding part as the air bubbles may not be smoothly discharged when a molding liquid is injected.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.